The 1999 series notes were originally printed with 2 letters and then 8 digits. I know that the letter "v" is not used in the serial numbers leaving 25 letters to use. If all combinations were printed from AA to ZZ that would be 625 combinations. I have collected about 350 of these combinations. Does anyone know if all 625 combinations were used? Were all serials used from 00000001 to 99999999 for each letter group or are there some short runs? The notes now are printed with a letter, a digit, a letter and then 7 more digits. How about these notes? Have all the combinations of letters been used already? It seems that even the "newer" notes are all getting dirty and nasty. Are there any plans for new 1 Yuan notes in China that people are aware of?